Press brake



Dec. l7, 1929.

R. T. HAZELTON PRES S BRAKE Filed oct. -25, 192e 5 sheets-sheet i s J' ATTORI/mrs [NI/ENTOR Dec. 17, 1929. R. T'. HAZELTON 1,739,902

' PRESS BRAKE Filed oct. 25, 1926 5 sheets-sheet 2 AT TORNEYS Dec. 17, 1929. R. T. HAzELToN 1,739,902

YRESS BRAKE Filed oct. v23. 1926 5 sheets-sheet s ATTORNEYS INVENTOR.`

Dec. l?, 1929. R. T. HAZELTON l,739,902

PRESS BRAKE Filed Oct. 25, 1926 5 Sheets-sheet 4 .1NVENToR. M

` A TTORNEYl Det. 17, 1929.

R. T-. HAzELToN l 1,739,902

PRESS BRAKE Filed Oct. 23. 1926 5 Sheets-Sheet- 5 I N VEN TOR.

A TTORNEYB Patented Dec. 17, 1929 UNITED STATES PATENT OFFICE ROBERT T. HAZELTON, OF CINCINNATI, OHIO, ASSIGNOR T0 THE CINCINNATI SHAPER COMPANY, OF CINCINNATI, OHIO, A. CORPORATION OF rOHIO rmissy BRAKE Application filed October 23, 1926. Serial No. 143,759.

My invention relates to the structure of press brakes of improved structural characteristics more particularly related to heavy duty brakes having a minimum of cumbersome frame parts.

There has been devised by me in the past a type of heavy duty press brakes in which the housings were formed of double steel plates bolted over intermediate cores, with overhanging portions of the plates serving to provide the centers on which the operating shaft for the ram was given a bearing. This enabled me to bring the line of thrust of the ecoentrics on the ram in a line parallel to and central of the vertical plane of the housings In the present invention, my main object is to accomplish a like purpose, using a single plate for a housing. This device is shown and described in my United States Patent No. 1,618,825, dated February 22, 1927. e

In the press brakes of the past, with which I am familiar, a heavy cross member is mounted across the tops of the housings and the thrust as applied to the ram is taken up by theA cross member. Such a heavy and cumbersome construction is avoided in both my older form of brake and the one forming the basis for this specification.

In order to eliminate an-operating shaft of large diameter, I so arrange the bearings and eccentrics that the shaft itself moves through an eccentric path while it is rotating, thus adding to the effect of the eccentrics and cutting down requirements as to size of parts, as will be more particularly explained.

In order to conserve heaviness of metal A used, I prevent localization of strains by developing the necessary angles in the frame- Work, ram and bed into curves. While as a principleof -engineering, this effect is known and calculations can be based thereon, I am not aware of anyone having devised a structure particularly in press brakes, where its application can be made to serve the duty of conservation.

I have provided a simple and effective ram operating device, and in arrangements for application of power and adjustment of the ram, have improved over present day press brakes which have come to my attention.

I accomplish my several objects bythat certain construction and arrangement of parts to be hereinafter more specifically pointed out and claimed.

In the drawings:

Figure 1 is a front elevation of the device.

Figure 2 is la central vertical section thereof.

Figure 3 is a detail side elevation of the frame, bed and ram, with parts broken away showing the ball and socket-like device for avoiding the developing of localized strains. Figure 4 is a similar view taken in front elevation of the same parts.

Figure 5 is a section taken centrally and vertically through one of the ram operating devices, viewing same from the side of thermachine.

Figure 6 is a like View viewing the parts as i in Figure 5 from the front bf the machine.

Figure 7 is a side elevation of o-ne of the.,

eccentric sleeves.

Figure 8 is a plan thereof. t

Figure 9 is a like View to vFigure 7 of the eccentric sleeve on the other housing. e

Figure 10 is a plan ,View of the eccentrlc sleeve of Figure 9.

In`the particular machine illustrated for the purpose of explaining my invention, I show the housings at 1, each consisting of a single steel plate, suitably supported on the floor or base. They can be made of com posite plates or unitary cast steel members, as desired. The power input may be pro.- vided by means of a pulley 2, which drives la shaft 3. On the opposite'side of the machine from the pulley, the sha-ft is equipped with a pinion 4, which drives the large gear 5.

The large gear 5 is located on the shaft 6, which carries the eccentrcs that operate ythe of the housings in anyaccepted manner.

Boxes 8 are secured to the ram, which pro- .vide ball sockets for the balls 9 of the ram.

The balls rest against plates 10 in the sockets, and are held down by socket plates 11, which are held down by shouldered nuts 11a, that screw down into the sockets over the tops of the balls. The nuts are held in place by means of small plates 12. These plates slide in notches 13 inthe sides of the box, and are held in clamping relation by mea-ns of screws 14, which pass through the slots15 in the plates.

The parts above described are referred to in the plural, becausethere is one'at each side of the machine, the two *being alike.

The pitmen which carry the thrust balls are formed as bifurcated members with a central depending tubular portion 16, within which is a screw 17. The screws carry the balls 9 integrally on their ends, and the screws are threaded into the tubular portions for purposes of adjustment of ram position. To revolve the screws and thus change the position of the ram with relation to the eccentrics which operate the pitmen, journal boxes 17a are set over the screws and support the cross shaft 18, that extends from pitman to pitman. Within the journal boxes are screws 19 which engage worm gears 20, that are keyed to the lower ends of the screws, above the balls. The journal boxes have portions 21 which house the gears, and the boxes are held against movement by being set over the gears, as shown more particularly in Figure 5.

The most important feature of the structure of the pitmen is that they are bifurcated. The single steel plate housings have the overhanging upper ends 22, and the two arms of the pitman structure as indicated at 23, are located one 'on each side of this overhanging portion, in such a way that the screws and balls depend in the plane of the housings and 1n a substantially vertical plane.

The balls thus being in the plane of the housings, and the thrust thereon being in the same plane, avoids torsional strainson the housings, and avoids the necessity of a heavy tzross beam connecting the two housings at the Figures 5 to 10 show most-graphically the mode of mounting the shaft 6, which operates the two pitmen. Holesl are formed in the portions 22 of the singlelplate housings, in'

which are the bushings 24. The eccentric i sleeves for the right hand end of the machine viewed as in Figure 1, are shown in Figures 5 and 8. The sleeves having triangular key keys 25 and theshaft-like key ways 26, and

suitable rectangular keys 27, both keys and ways being slightly tapered, are driven between them, to key the sleeves to the shaft. Otherwise the sleeves can be shrunk or keyed in any other way to the shaft 6. Also, the shaft 6 could' be omitted and the drive at the left side of the machine duplicated at the The central portion 32 of the is eccentric to the center of the shaft 6. As

a result of this structure, when the shaft is revolved by the gearing already briefly described, it moves through an eccentric path, which adds to the eccentric-ity of movement of the eccentrics, thus avoiding the use of a very large and heavy shaft, which ,wouldk otherwise be required in order to give enough metal inthe sleeves and still `provide for proper length of stroke of the ram.

The sleeve on the other side lhas four portions instead of three. The portions marked 28a and 29a are alike to portions 28 and 29 of the sleeve .firstly described, and the portion 32a is like the portion 32 of the first sleeve. The portio'n 33 of this left hand sleeve is developed on the true center of the central portions 32aof the sleeve, and is keyed to the gear 5, which has been described.

'Thus the'gear 5 does not have to move in an eccentric path, while the shaft does have to, and the structure makes for lightness and efficiency as will be obvious.

Instead of mounting the ram ball boxes in such a way as to subject the ram to a shearing strain, localized at the reduced end portions, I take particular care to avoid this. The boxes which have been referred to, are parts of plates 33a secured to the reduced ends of the ram in such a way that a curved lower face 34 of each box rest-s on a curved exposed upper edge 35 of the ram ends (Fig. 4).

The bed of the ram is formed of a heavy metal plate 36, which in this instance 4is the counterpart in shape, substantially to the ram only inverted. Thus it has the reduced lateral ends 37, and the deep central portion 38. The ends of the bed rest on projections 39 of the housing plates, one at each side of the machine (Fig. 1 and Figs. 3 and 4). It is also held in place by bolting it to the housings in any desired way;`

The bed is formed with a curved wall 4() at the lower edge of the portion 37, and the -housing plate is formed with a curved socket 41 at the upper edge of each shoulder, the curves being at right angles to each other. Shoes 42 are used to rest between the housing plate shoulders and the ends ofthe bed. These shoes are held in place by the parts between which they lie, and have a curved lower surface 43, to match the curve of the housing shoulders, and a curved top surface at riofht an les as at 44, to match the curves of the lied en s. v

In both instances I have pro vided a. bearing between the relatively supported parts, that dist-ributes the strain applied in doing work vover a wide area of the parts affected, which would not be the case were the bearing faces formed with right angles instead of curves. Roughly speaking, this is because there is no reduced cross section caused by a corner, where the metal is Weakest and where strains localize.

The various expediente and structural .elements referred to are all directed to the end of permitting the use of single plate housings without heavy cross beams or heads, and this permits of a less cumbersome, and more powerful press brake structure of extreme rig1dity in use, and .simple to set up. It can be shipped knocked down with considerable -of its mechanism in place 0n eachhousing,

and the parts readily assembled on the floor, which is not practical with housings that are connected across the top, and in which the force applied to the ram is directed along lines which lie inside of the vertical planes of the housings, as has been prior practice.v

Having thus described my invention What I claim as new and desire to secure byLetters Patent is 1. In a press brake the combination of housing means, a bed supported with relation thereto, and a ram supported thereon and movable with relation thereto, and means for applying pressure to the ram comprisinganI element moving in the vertical plane of the housing means, andhaving a bifurcated end to which force is applied and straddling said housing means, and means for applying said force, the same being mounted inthe housing.

2. In a press brake the combination of housings, a bed supported with relation thereto, and a ram suppUrted-thereon and movable with relation thereto, and means for applying pressure to the ram comprising elements moving in the vertical plane of the housings, and having bifurcated ends .to which force is applied and straddling said housings, and means for applying said force, the same being mounted in the housings, said housings being formed of individual plates of stee Y 3. In a press brake the combination of a pair ofhousings formed as ,individual plates of steel, a ram, eccentrics mounted in the housings in pairs, one on each sideof each housing, and elements mounted over the eccentrics, and having means thereon.c formengaging the ram. y'

4. In a press brake the combination of a pair of housings formed as individual plates of steel, eccentrics mounted in the housings in pairs, one on. each side of each housing, and elements mounted over the eccentrics, and having means thereon for engaging a ram, and a ram mounted to move vertically on said housings, said elements having members thereon to engage the ram along a line within the vertical lane of the housings.

5. In a press bra e the combination of a pair of housings formed as individual plates of steel, eccentrics mounted in the housings in pairs, one on each side of each housing, and elements mounted over the eccentrics, and having means thereon for engaging a ram, and a ram mounted to move vertically'on said housings, said elements having members thereon to engage the ram along a line within the vertical plane of the housings, said housings having overhanging portions in which the eccentrics are mounted whereby the elements apply force to the ram in substantially the line of movement of the ram.

6. In combination in a press brake, a pair of housings having sleeves set therein having at least Yone exposed eccentric, pitmen for operating the ram of the brake, set over the eccentrics, a driving shaft coupling the sleeves in the housings, and secured fast to said sleeves, and said sleeves in the portions set Within the housings formed eccentric to the shaft, and means for revolving the eccentric structure, whereby said shaft passes through an eccentric path during revolution.

7. In combination in a press brake, a pair of housings having sleeves set therein-having at 'least one exposed eccentric, pitmen for operating the ram of the brake, set over the eccentrics, a driving shaft coupling the sleevesin the housings, and secured fast to said sleeves, and said sleeves in the portions set Within the housings formed eccentric to the shaft, and means for revolving the eccentric structure, whereby said shaft passes through an eccentric path during revolution, said driving means having an element to be rotated, and means on one of the sleeves at least, and co-axial with the portions of said .thereto, and bearings intermediate the 'bed and housing comprising shoulders on the respectiveparts, and said sho-ulders arranged to have each a radius of curvature at the point of'support, for the purpose described, and a filler piece between the parts at said point of support, having matching radii of curvature.

10. In a press brake the combination of a supporting housing and a bed, bearings intermediate the bed and housing comprising shoulders on the respective parts and said shoulders arranged to have each a radius of curvature at the point of sup-port, for the purpose described, and a filler piece between the parts at said point of support, having matching curved surfaces, the radii of some of the surfaces being at right angles to each other.

11. In a press brake the combination of a supporting housing and a bed comprising shoulders on the respective parts, and said shoulders arranged to have each a radius of curvature at the point of support, for the purpose described, and a filler piece between the parts at said point of support, having matching radii of curvature, said matching curved surfaces, the radn ofsome of the surfaces being at right angles to each other. .y 25

12. In a press brake, a frame, anda ram ymoving' along the frame, and means support-ed by the frame and engaging the ram lto operate it, said ram having a curved edge where the force is applied in itsoperation,

and a member secured to the ram and directly receiving the applied force, said member hav- 13.. In a press brake the combination of housings, a bed supported with relation thereto, a ram supported on and movable along y' the housings, and means supported in the houslngs and engaging the ram, by which supporting means force is applied to the ram to move it with relation to the housing, said means. having elements thereof located on each side of each housing in such a position as to balance the load exerted 'against the housings.

14. In a press brake the combination of a housing, a bed supported with relation thereto, a ram movable along the housing, and 'means supported in the housing and engaging the ram, by which means force is applied to the ram tomove it with relation to the housing, said means having elements thereof located on each side of the housing in such a position as to balance the load exerted against the housing.

15. In combination in a press brake, a houslng, a. ram movable along the housing, and means for applying moving force to the ram, comprising an element mounted in the housing, rotary means on a fixed axis torevolve said element, the mounting thereof in the housing being concentric 'with the rotary means, and a pair of eccentrics developed on said element, and means on the ram engagin said eccentrics and Aoperated thereby. 16. n a. pxress brake the combination of a ousing and a bed rigidly secured ders, and means for rigidly securing the bed to the housing.

ROBERT T. HAZELTON.

v ing also a curved edge where it engages the 

